Biometric identification systems, such as fingerprint identification systems have been available for many years. They work well and are quite reliable when used properly. The ability of a fingerprint identification system to correctly match a fingerprint sample to a pre-enrolled fingerprint specimen stored in a biometrics database is directly proportional to the size of the fingerprint specimen within the database and its correlation with a submitted fingerprint sample.
A problem exists when using fingerprint identification systems where the enrolled fingerprint images or feature extracted representations are used for comparison with live scan plain impression fingerprint images submitted to the database system for a comparison match. Frequently, the submitted sample fingerprint image, although rich in feature detail, fails to be matched or recognized because the finger was not properly oriented on the imaging platen during the image capture process, or in the case of a small-area fingerprint scanner, the imaged area of the finger was not exactly the same as the area that was imaged to produce the fingerprint specimen that is stored in the database. In some situations, the finger may have been tilted to the side or may have been presented on the extreme fingertip end. The match request fails in these circumstances, not because of lack of detail, but because the detail does not represent the same surface of the finger as that which was originally enrolled in the database.